Boat-type wing-pontoon.



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e. H. c'unnss.

BOAT TYPE WING PONTOON.

APPLICATION FILED AUG-12.1916.

1,246,017. Patented Nov. 6, 1917.

4 SHEETSSHEET l.

G. H. CURTISS.

BOAT TYPEWING PONTOON.

APPLICATION FILED AUG. 12. 19l6.

Patented N 0V. 6, 1917.

4 SHEETSSHEET 2.

F165. I Fla.

awvewfo'c I GLENN HCuFzTlss.

G. H. CURTISS.

BOAT TYPE WING PONTOON.

APPL CATION FILED AUG-12.1916.

4 SHEETSSHEET 3- INvENToR GLENN HCURT155.

Patented Nov. 6, 1917.

G. H. CURTISS.

BOAT TYPE WING PONTOON.

APPLICATION FILED AUG. 12, I9I6. 1,246,01 7. Patented Nov. 6, 1917.

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Inventor GLENN H CUR-H55.

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GLENN H. CURTISS, OF BUFFALO, NEW YORK, ASSIG-N'OR TO CURTISS AEBOPLANE AND MOTOR COBPOR'ATION, A CORPOR TION OF NEW YORK.-

BOAT-TYPE WING-PONTOON.

Specification of Letters Patent.

Patented Nov. 6, 191 7.

Application filed August 12,1916. Serial No. 114,532. I

To all whom it may concern:

Be it known that I, GLENN H. CURTISS, a. citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Boat-Type" WVing Pontoons, of which the following is a specification.

My invention relates to aircraft equipment and has reference more particularly to wing pontoons for hydroaeroplanes or flying boats. V

Ordinarily wing pontoons are constructed to present a flat hydroplaning bottom having an angle of incidence considerably greater than the angle of incidence of the wings. In all pontoons itis essential that the connection with the aeroplane wing be absolutely rigid; that the bottom of the pontoon possess hydroplaning characteristics; and that the pontoon be constructed in substantially streamline form. Heretofore the pontoons plane of the center of air lift. The hydroplaning surface of the pontoon is therefore brought forward. To do this, without struchave been droppeddown quite some distance below the' Wings and effectually trussed to one or more of the wing beams, the resultant center of hydroplane lift lying considerably it? of the vertical plane of the center of air The above construction, although serviceable, is incapable of withstanding effectually the heavy strains incurred by use in rough water and in connection with flying boats and hydroaer oplanes of large size.

Many disadvantages, structurally, are found to exist. By the present invention it is proposed to locate the resultant center of hydroplane 11ft in the, approximate vertical turally changing the type of pontoon now extant, would require that the forward end of the pontoon extend considerabl that the supporting struts I extend rearplane of-th'e wing beams. Obviously, this arrangement would be impractical and conducive to greatly increased head resistance incident to flight. Moreover, the larger the pontoon the greater. the strains. Particularly is this true in rough water. Hence, to meet these conditions which arise through increased bulk and yet maintain the center of hydroplane lift at the poi t desired, it is in advance of the leading edge of the wlngs and proposed by this invention to construct the pontoon along radically different lines, z. 6.- lines which provide for the elimination of the flexible paddle often used and the marked angle of incidence heretofore required.

By the present invention is it proposed therefore; first, to increase the buoyancy or sustainingcapacity of the wing pontoon;

second, to morea'se materially its hydro- These advantages I attain in the particular manner and by the particular construction hereinafter pointed out.

In its broad aspect, each wing pontoon may be said topartake of the general characteristics and attitude of a boat. The hydroplaning surfaceis made an integral part of the pontoon body or hull and constructed to split or cut the water in traveling at speed over the surface thereof. From the bow end of the hull, the bottom, at the chlnes, ex-

tends downwardly and rearwardly to a point well aft where it is. slightly upwardly inclined or curved. The curvature of the keel is different. From a point where the keel and stem join, the keel extends abruptly downwardly and slightly rearwardly and then more horizontally rearwardly and slightly downwardl to a point approximately amidships w ere it continues aft on an upwardly and rearwardly inclined curve, terminating at its extreme after end at a point where the chine-stringersand stern post meet. This difl'e'rence in curvature between the chines and the keel will give to the hull bottom a convex form both longitudinally and transversely,- the convexity (transversely) decreasing gradually from a point well forward to flatness at the stern. The sides of the hull are bowed in streame tom; tom and aft and extend. at right angles to the deck which is horizontally flat or nearly so. Interiorly, the hull'is braced and trussed to secure rigidity and strength.

In the drawings, wherein like characters of' reference designate like or'corresponding parts throughout the several views:

Figure 1 is a longitudinal vertical sectional view of a wing pontoon having the characteristics of a boat and co nstructed in Fig. 6 is a fragmentary top plan View illustrating the manner in which the pontoon is fastened to its supporting wing;

Fig. 7 is a front elevation of a hydroaeroplane equipped with boat type pontoons to accordingly illustrate thesimilarity between the hydroplaning bottom of each pontoon and the main or center flotation body of the craft;

8 is a view similar to Fig. 1 illustrating a modification; I,

Fig. 9 is a top plan view of the modified pontoon illustrated in Fig. 8;

Fig. 10 is a transverse section on the line 10 -10 of Fig. 8.

Fig. 11 is a transverse section on the line 11 11 of Fig. 8, and

Flgs. 12, 13 and 14 illustrate details of the modification.

The pontoon structure which I consider preferred I have illustrated in Figs. 1-7 inclusive. With reference particularly to Fig. 7 wherein I have illustrated diagrammatically a hydroaeroplane equipped with wing pontoons of the present invention, the

numeral 15 designates the main or center flotation body, 16 the end flotation bodies or wing pontoons (each designated in its entirety), and 17 the aeroplanes or support- I ing surfaces, of which, in the diagram illus- The main or center trated there are two. flotation body 15 is of the well known Curtisstype which, when viewed in elevation (front) presents a hydroplaning surface of V-forin in transverse section, the angle of the V decreasing to flatness at a point approximately amidships where the usual rea'rwardly facing step (not shown) is formed. Excrescent structures or bilge fins continue the hydroplaning bottom of the main flotation surface laterally beyond the chines to increase the boat displacement. The foregoing and other well known features of the Curtiss machine characterize the hull. w

The wing pontoons 16 are much smaller memoir and like the wing pontoons of all hydroaeromachines arranged beneath the lower supporting surface, one. at each side of the longitudinal axis of the craft, preferably at the very tip of each wing. In form and attitude, the pontoons 16 are somewhat similar to the main flotation body 15 in that each has the" characteristics and water engaging position of a boat and in size is capable of sustaining not only the weight of the aeroplane wing beneath which it is arranged but each the additional weight of an adult in case of an emergency.

In construction, the Wing pontoons are alike, Each pontoon at its forward end is shaped to streamline form and equipped with a vertically pointed prow. The underneath surface of the pontoon or hull is generally flat and shaped both transversely and longitudinally to present to the water a hydroplaning surface of approved and accepted form. The hull sides throughout extend vertically and merge both fore and aft respectively into the stem and stern post later to be described. This construction will g-ive'to the pontoon a perfect streamline form and at the same time present a hydroplaning surface of increased area and one which iscapable of entering and split ting the wiiter in traveling at speed thereon. The transverse section of the hydroplaning bottom, by the action of water In constructing the pontoon, the keel 18 is first laid and the remaining structural elements assembled symmetrically with -respect thereto. The keel at its forward end extends vertically, the vertical prolon 21-,

tion constituting the stem of the hull which I have herein designated 19. From the stem aft, the keel is curved rearwardly and downwardly to a point 20 where the curvature continues more horizontally to a point 21 approximately amidships. At this .point the curvature swings gradually upwardly until an abrupt terminus is reached at the stern. The stern post to which the keel is fastened at its extreme after end is designated 22. The stem 19 and the stern post 22 extendvertically and substantially parallel.

Chine stringers 23, symmetrically and oppositely curved or bowed both horizontally and vertically, interconnect the stem 19 and the stern post 22. The curvature of the chine stringers 23 although somewhat similar to the curvature of the keel 18 is less marked and more regular, having agradually downward and rearward curvature from stem to stern. This difference in curvature-between the chine stringers and the keel will give to the hydroplaning bottom I the desired or required form. At the extreme forward end of the pontoon the hy droplanmg bottom is characterized by convexity of V-form, the angle of the V at this point being relatively small. From the forward end aft the angle increases gradually,

accordingly decreasing the convexity to flatness at the stern. Fig. 1 considered in connectlon with the transverse sections, Figs.

3, 4 and 5, illustrate clearly the shape and concave, this curvature, while hydroplaning, directing the displaced water laterally and downwardly that the cushioning -fea-' ture may result.

Interiorly, the hull or pontoon is bracedand trussed both transversely and longitue dinally after a fashion illustrated in F igsQ 1 and 2. Deck stringers 24 which extend parallel with the chine stringers 23, and

side stringers 25, constitute with the stem 19, the stern ,post 22, the keel 18, a false keel 26, an upper breast hook 27, a lower breast hook 28, an upper tail plate 29, and a lower tail plate 30, a frame to which the planking,

flooring, beams and struts are fastened.

Deck beams 31 interconnect the deck stringers 24, longitudinally brace.- the stringers, and at the same time afford a base orbed for i the deck planking 32. Side struts or frames 33 interconnect the deck stringers and the chine stringers and like the deck beams 31 afford a bed (not for the 'deck planking) but for the side planking 34. The flooring or bottom planking 35-is fastened to the bent floor beams 36 which interconnect the chine stringers and engage-equidistant from their ends with the keel. Bulkheads 37 divide the pontoon .or hull transversely'into watertight compartments although the forward bulkhead, designated 38, isnon-w-atertight as shown.

To brace the hull from stennto stern, cross braces 39 and crossed diagonals 40 are located interiorly thereof. The aftermost crossed diagonals engage respectively with the flooring at the chine stringers and with the deck at the deck stringers. The intermediate crossed diagonals are similarly arranged though oppositely inclined. They form with the rear crossed diagonals an inverted V-brace in side elevation. In other words, both sets of diagonals engage with the chine stringers in such manner that they form the apex of. the inverted V-brace.

-. Battens 41 and V-arranged braces 42- also interiorly and strongly brace the hull. The cross braces 39 are preferably located substantially amidships or at'a point in the approximate vertical plane ofthat point designated 21 where the keel 18 begins to assume an upwardly and rearwardly inclined curve.

While any appropriate fastening ineans may be used it is preferred that the ontoons lie close upunder the aeroplane w ngs for securement directly to the wing spars herein designated 43. Bolts 44 engage with the wing spars at opposite sides thereof (so as not to weaken them) and with the pontoon beneath the deck planking 32. A plate 45 is arranged over the bolt terminals extendedabove the wing spar to constitute with nuts 46 a fastening means. The arrangement of the. pontoon with respect to the wing spars is best illustrated in Fig. 1.

. By constructing the wing pontoons in the manner described and fastening each wing pontoon closeup under the wing with the sides of the pontoon extending vertically, or nearly so, a flotation body of considerable displacement and-buoyancy is produced. A pointed prow will'permit the hydroplaning surface to be brought considerably forward and in fact forward to a point in the approximatevertical plane of the entering edge of the wing. This'construction not only increases the hydroplaning area but eliminates the wing bending moment ordinarily found where the center of hydroplane lift is located aft of the rear wing snarbeneath which the pontoon is arranged.

The depth of applicants pontoon is ap' proximately the same both fore and aft with its-greatest depth substantially amidships.

The depth at the prow in fact is quite sub stantial and the same may be said to extend downwardly substantially vertically from the, wing near to the water surface. Seaworthiness of the pontoon is thus increased and the anti-skid surface actually enlarged whereby greater stabilitv in flight will result. The head resistance is .in no way increased. Briefly, the pontoon may be said to partake of the characteristics of a boat in structure, position, function and design, yet as compared with the center float the pontoon sustains no substantial portion of the total load.

-With reference to the modification illustrated in Figs. 8-14 inclusive, it will be noted that this pontoon is'diflerently constructed. In the modification, the stem 19' extends horizontally rather than vertically and'the keel 18, false keel 26 and chine stringers 23 extend aft therefrom on a downward and readward curve and sub stantially' in parallelism throughout the greater portion of their length. The prow end of the pontoon is thus broad and flat. At the rear, the chine stringers 23 merge and engage at a point where the stern post 22 and keel 18' are joined. Although having a convex hydroplaning bottom from stem to stern, the convexity, unlike that dishydroplane bottom merges gradually into flatness both fore and aft. In other respects, the pontoon is quite similar to that. which I have designated as preferred. Deck' stringers 2 L interconnect the. stem and stern post-and with deck beams 31 constitute a bed for the deck 32. Side frames or beams 33 extend from the deck stringers 2i to the chine stringers 23 vertically and in parallelism to afiord a support for the side planking 34 Bent floor beams 36 join the chine stringers and engage with the keeL' Other structural details such as the water tight bulkhead 37, the crossbracing- 39 and bottom planking 35 will be understood by reference to Figs. 8 and 11. If

desired, drain plugs 50' (may be-provided.

In both instances, the pontoon structure is of a streamline form and equipped with ample hydroplaning surface to insure the desired hydroplaning action in use. The integrally formed V-bottom disclosed is particularly desirable in that each pontoon may thus partake ofthe characteristics of a boat and afiord, in emergency,a means whereby the aviator or other person if thrown into the water may regain control v of his'machine by climbing onto the wing said forward end being distantly removed pontoon and after gaining a footing proceed via the wing to the main flotation body. It is for this reason as well as the increased hydroplaning area produced that the wing pontoons are constructed in size large enough to sustain in addition to the weight of the aeroplanes, an adult person.

f While in the foregoing I have illustrated and described wing pontoons of. a more or less specific construction, it is to be understood that I do not intend to limit myself except in so far as the claims demand.

In conclusion, it is' to be noted that the sides. of the hull structure extend perpendicularly to the aeroplane surface; that the depths of the pontoon are approximately equal both fore and aft and that I have 'produced an integrally formed hydroplaning bottom transverselyconvex from the bow hydroplane bottom of substantially ll-form in transverse section at its forward end.

1 mea ow:

fromthe plane of the wing beneath which it is disposed.

3. In a hydro-aero-machine, the combination with aeroplane wings, of a main flotacaf tion body having the characteristics and attil tude of a boat,-the wing pontoons having a cut-water bow and a transversely convxed bottom, said bottom'being in hydroplaning form and so located with. respect to said aeroplane wings that its resultant center of hydroplane lift lies substantially beneath the center of lift.

4. In a hydro-aero-machine, the combination with aeroplane wings, of wing pontoons including a hydroplaning bottom'disposed substantlally uniformly distant from said wing, and forwardly converging substantially vertical sides built up rom said bottom to provide at the forwardend of the pontoon'a out water bow. 5. In a hydro-aero-machine, the combination with aeroplane wings, of wing .pontoons including a hydroplaning bottom disposed substantially uniformly distant from said aeroplane Wings, trussing for said bottom, and sides built up from said bottom to said wings, said sides 'inclosing said trussing and giving to the pontoon the characteristics and attitude of a boat.

v 6. In a hydro-aero-machine, the combination with aeroplane wings, of win pontoons having a transversely. convexediydroplaning bottom anda cut-water bow, said bottom underlying saidaeroplane wings and terminating forwardly at a'point in the approximate vertical plane of the leading edge of said wings and at a point distantly removed therefrom.

7. In a hydro-aero-machine, the combination with aeroplane wings, wing pontoons including a hydroplane bottom surface hav-.

ing its forward portion characterized by transverse convexity. and sides built up from said bottom in such, manner that-at the said forward end the pontoon is given a streamline entry and a cut-water how;

8. In a hydro-aero-machine, the combmation with aeroplane wings, of wing POD? :toons includin a hydroplaning bottom disposed substantlally uniformlydistant from said aeroplanewing throughout its length,- said bottom being characterized by transverse convexity, the convexity decreasing gradually from stem to stern, and sides built up from said bottom to form'therewith a pontoon of substantially boat form.

9. In a hydro-aero-machine, the combination with aeroplane wings, of wing pontoons including a hydroplaning bottom disposed substantially uniformlydistant from said wings throughout its. length, said bottom being characterized by longitudinal and transverse saliency, the saliency in the transverse plane increasing gradually togiving to the pontoon a cut-water bow;

, to said wings, said sides forming 10. In a hydro-aero-machine', the combination with aeroplanewings, of wing pontoons arranged beneath said wings, each pontoon comprising a 'hydroplane bottom disposed vertically distant from said wings throughout its length, said ,bottom commencing at a point in the approximate vertical plane of the leading edge of said wings whereby the resultant center'of hydroplane lift lies approximately below the center of lift, and sides built up from said bottom with said bottom a pontoon having the characteristics and attitude-of a boat.

11. Ina hydro-aero-machine, the combination with aeroplane wings, of wing pontoons having a forward depth approximately equal to the depth aft, a hydroplaning bottom, and substantially Vertical sides 4 built up from said bottom, said sides convergin upwardly to provide in efl'ect a cutwater ow.

12. In a hydro-aero-machine, the combination with aeroplane wings, of win pontoons comprising a hydroplaning ottom disposed vertically distant from said win such that the depth of the pontoon may e approximately equal from stem to stem,

said bottom in transverse section being characterized by saliency, the saliency increasing toward the stern, means directly trussing said bottom to the aeroplane wings, and sides built up from said bottom to said wings to inclose said trussing, said sides converging both fore and aft for stream-line purposes and for the purpose of giving to the pontoon a cut-water bow.

In testimony whereof I aflix my signature;

GLENN H. CURTISS. 

